This study concerns a prospective, longitudinal investigation of social and intellectual behavior of children with schizophrenic mothers, schizophrenic fathers, and two schizophrenic parents. As groups, these children are known to be at high risk for the eventual manifestation of schizophrenia. The primary purpose is to procure teacher ratings of classroom behavior and objective archival data on sholastic performance, attendance and conduct at school for the children of schizophrenic parents and matched controls. Approximately 20% of the sample will be selected as behaviorally maladjusted and consequently most vulnerable to subsequent emotional disorder. Contemporary behavioral comparisons will be made between the genetic risk groups and controls. Behavior will be correlated with other neurophysiological and clinical variables. Tests of theoretical predictions about vulnerability to emotionality will be made. Attention will be given to factors that differentiate vulnerable and resistant children within the high genetic-risk groups. The subjects in this study will be 147 children of one schizophrenic parent, 33 children of two schizophrenic parents, 65 children with a psychiatrically disordered (but not schizophrenic) parent, and 213 children of normal parents. The age range of the children upon initial examination is 7-12 years. Follow-up behavioral assessment will be made at 13-18 years of age. Long-term goals are to understand the behavioral precursors of adult schizophrenia, to develop longitudinal theory about the causes of the disorder and to devise procedures for early identification and preventive intervention.